1. Ad Hoc Mobility Management With Uniform Quorum Systems Zygmunt J. Haas, Senior Member, IEEE and Ben Liang, Student Member, IEEE Networking, IEEE/ACM Transactions on Volume: 72 April 1999, pp.228-240

2. Sawa Yang Outline Introduction The Mobility Management Scheme over a Virtual Backbone The Network Partitioning The Cost Analysis Conclusion

3. Sawa Yang Introduction This paper proposed –A distributed mobility management scheme Uniform Quorum Systems (UQS) ad hoc network The framework of this paper –Virtual backbone The goal of this paper –Mobility management

4. Sawa Yang The Mobility Management Scheme over a Virtual Backbone Backbone node Non-backbone node

5. Sawa Yang The Mobility Management Scheme over a Virtual Backbone A

6. Sawa Yang The Mobility Management Scheme over a Virtual Backbone To assume the Quorum is –{{1, 2, 3} {1, 4, 5} {2, 4, 6} {3, 5, 6}} {2, 4, 6} {3, 5, 6} {1, 2, 3} {2, 4, 6} {3, 5, 6} {2, 4, 6}

7. Sawa Yang The Mobility Management Scheme over a Virtual Backbone There are three ways in which locations are updated in the databases: – Call-origination update: – Location-change update: – Periodic update:

8. Sawa Yang The Mobility Management Scheme over a Virtual Backbone For example

9. Sawa Yang The Mobility Management Scheme over a Virtual Backbone Node4 multicast to {1, 4, 5} NodeA’s ID nodeA’s location The update time For example

10. Sawa Yang The Mobility Management Scheme over a Virtual Backbone query For example

11. Sawa Yang The Mobility Management Scheme over a Virtual Backbone Node2 multicast to {1, 2, 3} For example

12. Sawa Yang The Mobility Management Scheme over a Virtual Backbone Node1 reply to node2 A belongs to node4 For example

13. Sawa Yang The Mobility Management Scheme over a Virtual Backbone For example

14. Sawa Yang The Mobility Management Scheme over a Virtual Backbone Backbone node 2 has been disconnected from the network the mobile host B may be chosen to replace the detached node

15. Sawa Yang The Network Partitioning

16. Sawa Yang The Network Partitioning belongs to the “square” partitioning For example1:

17. Sawa Yang The Network Partitioning For example1: Node b2 multicast to {a1, a4, a5}

18. Sawa Yang The Network Partitioning For example2: query

19. Sawa Yang The Network Partitioning For example2: Randomly queries a “square” quorum {a1, a2, a3}

20. Sawa Yang The Network Partitioning For example2: Reply

21. Sawa Yang The Network Partitioning For example2:

22. Sawa Yang The Cost Analysis The Effect of Mobility on Cost Optimization

23. Sawa Yang The Cost Analysis The Effect of Mobility on Cost Optimization

24. Sawa Yang The Cost Analysis The Effect of Availability on Cost Optimization

25. Sawa Yang The Cost Analysis The Effect of Availability on Cost Optimization

26. Sawa Yang The Cost Analysis The Effect of Call-Loss Penalty on Cost Optimization

27. Sawa Yang Conclusion The virtual backbone is dynamically maintained The system is robust against database failures Since a network may have larger than the optimal number of databases –partitioning the network nodes into groups –The groups can form the optimal quorum system. Future work –Resource sharing